This invention concerns an inhalation valve (113) adapted to be disposed on an inhalation duct (110) of a breathing assistance apparatus to regulate a supply of a respiratory gas from a pressurized respiratory gas source (100) to a patient through the inhalation duct, the inhalation valve comprising a valve body having:an orifice (1130) configured to connect to the inhalation duct, anda moving element operable to block the orifice in a closed position, and to at least partially free the orifice in an open position, the moving element including a recess (1131) for aligning with the orifice to allow the gas from the gas source to pass through to the inhalation duct in use, andwherein the inhalation valve is adapted to be controlled by a control unit (51) which is distinct from the pressurized respiratory gas source.
